The toolbar icons (and other images) for jEdit are stored within the jedit.jar file (found at org/gjt/sp/jedit/icons)

These icons are PNG files (except for a few than are GIF images) and are loaded into jEdit are startup.

Once jEdit is running, you can assign custom icons to the toolbar by going into Utilities -> Global Options -> Tool Bar and editing or adding a command, and assign an icon by loading an image file.

There is another method of loading custom icons. (Which requires jEdit 4.2pre6 or later.) To do this, you will need to create a directory named 'icons' and put in any icons you wish to use by giving them the proper names. For instance if you want new icons for Cut, Copy, and Paste, you would need to name the files Cut.png, Copy.png, and Paste.png, respectively. (For a list of all of icons jEdit uses, you'll need to get at the icons stored in the jedit.jar file mentioned above, see below for instructions on how to do this.)

Once you have the icons you desire in your 'icons' directory, you will need to create a jar file. If you are familiar with the command line it's as simple as typing:

jar cfv customicons.jar icons

while in the directory containing your 'icons' directory.

Once this is done, you will need to copy the 'customicons.jar' to your 'jars' folder. This is located within your .jedit folder - normally found in your home folder.

There is one more step to get the icons to load. You'll need a startup script written in Bean Shell. (See Startup Scripts for more on this.) Create a file named 'customicons.bsh' and save it into the 'startup' folder of your .jedit folder.

The startup script should contain the following line:

GUIUtilities.setIconPath("jeditresource:/customicons.jar!/icons/");

That will tell jEdit to load the customicons.jar file we created.

Once this is all done, you can start jEdit and any replacement icons in your customicons.jar file will replace the normal jEdit icons. The normal jEdit icons will still be loaded and appear when you do not have a replacement icon in your jar file. Remember to go into Utilities -> Global Options -> Tool Bar to see the new choices under 'Use built-in icon' when you add or edit a toolbar command.